Re: Gutenprint 5.3.4: only on 32-bit failures with "Image is too long/wide for the page" for certain PPDs

Solomon Peachy <[email protected]> Sun, 5 Sep 2021 19:26:31 -0400

Newsgroups	gmane.linux.printing.gimp-print.devel
Message-ID	<[email protected]>

On Sun, Sep 05, 2021 at 06:16:10PM -0400, Robert Krawitz wrote:
> Sigh...have to figure out how to fix this.  Maybe we have to allow 
> something like a millipoint of slop.  Interesting that it seems to 
> have only hit the dyesub printers; is the issue that those are the 
> only ones with non-integer widths (in points)?

Yeah, I can't speak for every other family but inside the dyesub driver, 
all dimensions are specified in terms of pixels, but converted to points 
for external consumption.

I think it's reasonable to truncate anything smaller than a millipoint, 
though just patching that failing test to allow for a little slop seems 
like a bandaid when there very may well be other related lurking issues that
are ultimately due to a platform-specific FP semantics problem.

So I question whether Gutenprint is relevant for a >20-year-old 
Pentium3-era PC -- and this OpenSUSE build is actually targeting even 
older Pentium1-era systems that a $5 Raspberry Pi Zero would easily run 
circles around.

Perhaps the correct thing to do is force these older targets to use 
"correct" IEEE754 FP math through some extra GCC flags (-ffloat-store 
might be sufficient), which would hurt performance (on an already 
relatively glacial platform) but would mean we'd not need to make 
otherwise unnecessary algorithmic spelunking..

  https://gcc.gnu.org/wiki/x87note
  https://gcc.gnu.org/wiki/FloatingPointMath

 - Solomon
-- 
Solomon Peachy			      pizza at shaftnet dot org (email&xmpp)
                                      @pizza:shaftnet dot org   (matrix)
High Springs, FL                      speachy (libra.chat)

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